The present invention relates to floors, and more particularly, to hardwood floors having a wear layer supported over a base by compressible pads and a sleeper assembly, or substructure, which includes parallel rows of nailing strips for securing the wear layer.
Wood floors remain popular for athletic and residential applications, for a number of reasons including aesthetics, quality, stability, ease of maintenance, durability, etc. One popular type of wood floor employs parallel rows of tongue and groove floorboards, laid end to end, across the entire floor surface.
Particularly with hardwood sports floors used primarily for athletics, such as basketball, it is desirable to provide some degree of cushioning, or impact absorption, for the upper surface of the floor relative to the base, or underlying surface. This is typically done by supporting the floorboards above the base via pads, and in most cases the floorboards are secured to the top surface of some intermediate structure, with the pads located below the intermediate structure. The use of pads in this manner creates an open air space, or air break, between the floor and the base, thereby minimizing moisture ontake by the intermediate structure or the floorboards, which are usually made of wood. If the structure does not include some mechanism for attachment to the base, the floor is said to be xe2x80x9cfree floatingxe2x80x9d relative to the base.
In some cases it is desirable to secure, or anchor, the floor to the base, primarily for stability and to minimize the potentially adverse effects of floorboard expansion and contraction which may occur as a result of moisture ontake and/or egress as humidity levels change with the seasons. Also, this moisture-caused expansion and contraction of floorboards adversely affects the performance uniformity of the floor. Thus, anchoring the floor helps to assure uniformity in performance. These dual objectives, to resiliently support the floorboards above the base and to anchor the floorboards to the base, are not easy to achieve simultaneously. Because of this situation, there have been a number of recent developments in the athletic hardwood floor industry.
More specifically, assignee""s U.S. Pat. No. 5,388,380, entitled xe2x80x9cAnchored/Resilient Sleeper for Hardwood Floor Systemxe2x80x9d (xe2x80x9cNiese ""380xe2x80x9d) and issued in the name of Mike Niese, discloses several anchoring arrangements for anchoring attachment members to a base, with the attachment members supported on pads above the base and anchored in a manner which does not precompress the pads. Generally, Niese ""380 relates to resiliently anchoring parallel rows of relatively narrow elongated attachment members which are spaced from each other.
Another patent of the present assignee, U.S. Pat. No. 5,609,000, entitled xe2x80x9cAnchored/Resilient Hardwood Floor Systemxe2x80x9d and also issued to Mike Niese (xe2x80x9cNiese ""000xe2x80x9d), discloses, among other things, some variations in the intermediate structure of the floor which resides between the floorboards and the pads. These structural variations maintain the same benefits of being anchored to the base in a resilient manner, yet in a manner which does not precompress the pads, while also to some extent facilitating the manner of simultaneously achieving these objectives.
For these floors, as perhaps with all floors, there remains a high customer demand for improvements such as lower cost, shorter installation time, uniformity in performance, sufficient air flow, easier handling, and reduced quantity of materials, without any reduction in the floor""s other attributes, such as being anchored and resilient but with no pad precompression, or only minimal pad precompression.
It is therefore an object of the present invention to optimally achieve these customer demands, primarily the demands for reduced costs and shorter installation time, for a floor which is anchored to a base and/or resiliently supported above a base.
The present invention achieves the above-stated objects via a floor substructure attachment member, i.e. a sleeper assembly, having an elongated lower panel with pads residing along the bottom surface, and a pair of spaced nailing strips located on the top surface of the panel along the longitudinal edges. Between the rows of top nailing strips and the bottom pads, which are preferably in rows there below, the member includes one or more designations, preferably predrilled holes aligned in a row, for anchoring the substructure member to a base via anchors, if desired.
The sleeper assemblies, or substructure members, are laid out end to end in spaced rows over a base, and oriented perpendicular to the orientation of the floorboard rows located thereabove. To achieve proper spacing between adjacent rows of substructure members, during installation spacers may be placed temporarily between adjacent rows of substructure members. This results in equidistant spacing of the rows of nailing strips across the entire floor, even though there are open spaces between adjacent rows of substructure members. If the rows of substructure members are to be anchored, this can be done by extending anchors through the predrilled holes and then anchoring them into the base via conventional methods. Preferably, prior to driving, a hole is drilled into the base, with drill access to the base being provided by the predrilled holes in the panel. The upper floorboards are fastened to the nailing strips, preferably by nails (or other industry standard fasteners, such as staples) driven at an angle, as is well known in the hardwood floor industry.
With this invention, due to the width of the elongated substructure members, combined with the two spaced rows of pads at the bottom of the members, the substructure members are very stable once laid in place on the base. It is virtually impossible to tip them over. Such tipping has been known to occur relatively frequently with narrow attachment members supported on only a single row of pads, a substructure commonly used for hardwood floors. Obviously, such tipping over creates delays and aggravation for installers. Such tipping also heightens the potential for misalignment of attachment members, which may lead to non-uniformity of the floors. Thus, this invention simplifies installation and eliminates unnecessary delays. Also, the rows of these substructure members are relatively easy to keep in alignment once laid in place over the base. This feature is extremely beneficial in free-floating flooring systems.
Compared to the relatively narrow attachment strips which have been commonly used, the relatively wide and flat engineered panels of these substructure members are not subject to curvature or warping from moisture. Again, once laid in place on the base, the substructure members of this invention stay in place, and stay in straight lines. By using plywood for the panels and the strips, the members can be made in lengths of up to eight feet, or even longer, but still at relatively low cost. The longer the members, the easier and more expedient the installation.
Compared to prior subfloor comprising parallel rows of narrow attachment members, this invention uses two rows of nailing strips for every one row of attachment members. Thus, the number of installed rows of the floor""s intermediate structure is halved. If the substructure members are anchored, the installation requires only one row of anchors per two rows of nailing strips. Again, this represents a reduction in installation and handling time and lower labor costs, but with a high degree of stability.
This invention also reduces material costs. The panels of the substructure members may be cut from plywood, or any other suitably strong material of relatively uniform thickness. The nailing strips can also be formed of similar material, with similar thickness and length but significantly less width.
Compared to other floors, the floor of this invention achieves incredibly high stability and strength, but with significantly less material. When the floorboards are secured to the nailing strips, with the nailing strips secured to the lower panel, the combined structure has a stiffening effect similar to an xe2x80x9cI-beamxe2x80x9d or a structural channel. Thus, the invention achieves a high strength floor with a relatively low material cost.
According to a preferred embodiment of the invention, an anchored/resilient floor includes an upper wear layer of floorboards supported in spaced relation above a base by compressible pads, with spaced rows of substructure members residing between the pads and the wear layer. Each substructure member includes an elongated panel with a pair of spaced rows of pads secured to the bottom surface along opposite edges, and a corresponding pair of rows of nailing strips secured to the top surface, above the pad rows. The wear layer is secured by fasteners to the substructure members, via the rows of nailing strips. The rows of substructure members are spaced from each other a distance such that the rows of nailing strips are generally equidistant from each other throughout the entire floor.
The panels may also include a selected member of designations, preferably a middle row of predrilled holes, extending parallel to and residing between the two rows of nailing strips. If the substructure members are anchored, the anchors are driven into the base through the holes, preferably into holes already drilled into the base. The anchors may be configured so as to include a depth stop, or any other physical structure for preventing precompression of the pads which could otherwise result from pressurized shooting of the anchors into the base. However, compared to other substructures for anchored/resilient floors, this invention reduces the need to use a depth stop or some other depth controlling structure. This is because the pad rows are spaced away from the center row of designation holes and because the relatively thin lower panel flexes during shooting of the anchors into the base. As a result, even without a depth stop there may not be any precompression of the pads, or only negligible precompression. The anchors may include a lubricating collar, such as nylon, to prevent squeaking during relative movement between the panel and the anchor. Because the fasteners which hold the wear layer are spaced laterally away from the anchors, and also because the anchors are also spaced laterally from the pads, this inventive floor has fewer squeaks. If desired, the predrilled holes in the panel may also be somewhat elongated in the elongated direction of the substructure members, to allow some lateral movement of the floorboards.
Once installed, the heads of the anchors are spaced sufficiently from the bottom of the wear layer, i.e. the floorboards, so that downward deflection of the floorboards upon impact to the surface of the floorboards, as the pads compress, will not result in contact between the head ends of the anchors and the bottoms of the floorboards.
These and other features of the invention will be more readily understood in view of the following detailed description and the drawings.